We investigated how children’s strategy selection on different problem types was influenced by whether two or three strategies were available in a computational estimation task. Importantly, we examined the influence of individual differences in working memory updating on these effects. Third and fourth graders (N = 725) were asked to indicate the best strategy for two-digit addition problems (e.g., 47 + 24) without calculating estimates. Homogeneous problems (i.e., both unit digits smaller than 5 or larger than 5) and heterogeneous problems (i.e., one operand’s unit digit smaller than 5 and the other’s unit digit larger than 5) were included. Children completed selection tasks under two conditions: (a) a three-strategy condition, in which they could choose among the rounding-down strategy (i.e., rounding both operands down), the mixed-rounding strategy (i.e., rounding one operand down and the other operand up), and the rounding-up strategy (i.e., rounding both operands up), and (b) a two-strategy condition, in which they could select between the rounding-down strategy and the rounding-up strategy only. As expected, children chose the best available strategy more often under the three-strategy condition than under the two-strategy condition and more often on homogeneous problems than on heterogeneous problems. Importantly, these effects were moderated by children’s updating capacities. That is, children with less efficient updating showed worse selection performance on heterogeneous problems than on homogeneous problems under both conditions. In turn, children with more efficient updating showed comparable performance for both problem types under both conditions. These findings have important implications to further our understanding of underlying processes in children’s strategy selection in computational estimation.

我们调查了儿童对不同问题类型的策略选择如何受到计算估计任务中是否有两种或三种策略可用的影响。重要的是，我们检查了工作记忆更新的个体差异对这些影响的影响。三、四年级学生（N = 725) 被要求指出两位数加法问题（例如，47 + 24）的最佳策略，而无需计算估计值。包括同构问题（即两个单位数字都小于 5 或​​大于 5）和异构问题（即一个操作数的单位数字小于 5，另一个操作数的单位数字大于 5）。孩子们在两种条件下完成选择任务：(a) 三策略条件，他们可以在向下舍入策略（即向下舍入两个操作数）、混合舍入策略（即向下舍入一个操作数和另一个操作数向上）和四舍五入策略（即，将两个操作数向上舍入），以及（b）双策略条件，其中他们只能在向下舍入策略和向上舍入策略之间进行选择。正如预期的那样，儿童在三策略条件下比在二策略条件下更频繁地选择最佳可用策略，并且在同质问题上比在异质问题上更频繁。重要的是，这些影响被儿童的更新能力所缓和。也就是说，在两种情况下，更新效率较低的孩子在异构问题上的选择性能都比在同构问题上表现的更差。反过来，在两种情况下，更新效率更高的儿童在两种问题类型上表现出相当的表现。这些发现对我们进一步理解计算估计中儿童策略选择的潜在过程具有重要意义。